KR20190107090A - Hologram Light Detection and Measurement - Google Patents

Abstract

A light detection and surveying system is disclosed that includes a light source arranged to output light having a first characteristic and arranged to scan a scene. The spatial light modulator is arranged to receive light from the light source and to output spatially modulated light according to the computer generated hologram represented thereon. The hologram controller is arranged to output a plurality of computer generated holograms to the spatial light modulator. Each computer-generated hologram is arranged to form a corresponding light footprint in the scene. The hologram controller is arranged to change the position of the optical footprint within the scene. The light detector is arranged to receive light having a first characteristic from the scene and to output a light response signal. In embodiments, the plurality of first holograms are arranged to provide a first scanning in the scene, and the hologram controller receives the first light response signal in response to the first scanning to generate a plurality of first holograms based on the attributes of the light response signal. It is arranged to determine the second hologram.

Description

Hologram Light Detection and Measurement

The present invention relates to an optical projector. More specifically, the present invention relates to a holographic projector, a holographic projection system, a method of controlling a projector and a method of controlling a holographic projection system. Embodiments relate to a light detection and surveying system. Some embodiments relate to light detection and measurement methods. Some embodiments are directed to a method of controlling an optical footprint in a light detection and surveying system. Some embodiments are directed to a method of scanning a scene with a computer controlled optical footprint.

Light scattered from the object includes amplitude and phase information. Such amplitude and phase information can be captured, for example, on photosensitive plates by well-known interference techniques to form "holograms" comprising holographic recordings or interference stripes. The hologram may be constructed by irradiating light appropriate to form a two-dimensional or three-dimensional holographic reconstruction or replay image representing the original object.

Computer-generated holography can numerically simulate the interference process. Computer-generated holograms (CGH) can be calculated by techniques based on mathematical transformations such as Fresnel or Fourier transforms. Holograms of this type may be referred to as Fresnel or Fourier holograms. A Fourier hologram can be considered as a Fourier domain representation of an object or a frequency domain representation of an object. CGH can also be calculated by, for example, coherent ray tracing or point cloud technique.

The CGH can be encoded on a spatial light modulator (SLM) configured to modulate the amplitude and / or phase of incident light. Light modulation can be achieved, for example, using electrically addressable liquid crystals, optically addressable liquid crystals or micromirrors.

The SLM may include a plurality of individually addressable pixels, which may be referred to as cells or elements. The light modulation scheme may be binary, multilevel, or continuous. Alternatively, the device may be continuous (ie not composed of pixels), and thus light modulation may be continuous throughout the device. The SLM may be reflective in that modulated light is reflected from the SLM and output. The SLM may be transmissive in that modulated light is output through the SLM.

A holographic projector can be provided that projects an image using the above technique. Such projectors are being applied, for example, to head mounted displays (HMDs) including head up displays (HUDs) and near eye devices.

Aspects of the invention are defined in the appended independent claims.

A method of detecting and measuring light is provided that includes illuminating a scene with spatially modulated light by outputting a plurality of computer generated holograms to a spatial light modulator and illuminating the spatial light modulator with light having a first characteristic. Each hologram is arranged to form a corresponding optical footprint in the scene. The method may further comprise moving the optical footprint in the scene. The method may also include receiving spatially modulated light reflected from the scene.

In accordance with the present invention, the optical footprint can achieve discrete movement from a portion of the scene to another portion of the scene. In particular, the optical footprint can be rearranged immediately within the scene. The optical footprint may be instantaneously jumped from the first point of the scene to the second point of the scene. This is accomplished by forming an optical footprint using dynamic holography. This method can be used to dynamically change the size, shape, orientation and / or position of the optical footprint.

The method may further comprise moving the spatially modulated light back and forth between two or more regions of the scene to perform interleaved scanning of regions within the scene.

The method may further comprise intelligent scanning of the scene using feedback from the photo detector to determine how and where to perform the next scanning. This may include selecting at least one computer generated hologram from a memory or calculating at least one computer generated hologram comprising calculating at least one computer generated hologram in real time based on the received signal. .

In this specification, the term “light footprint” is used to refer to an illumination pattern formed in a scene by each hologram. Thus, the optical footprint is the area where there is light in the scene. The light can be pulsed. The light may have uniform brightness over its area. The optical footprint can be characterized in size, shape and orientation. The light detection and surveying system disclosed herein can be used to form a time sequence of optical footprints that vary and / or move within a scene. Preferably, the dynamic reconfigurable holographic techniques disclosed herein can be used to control the optical footprint and the parameters of the optical footprint in real time.

The term "hologram" is used to refer to a recording that includes amplitude information or phase information about an object, or some combination thereof. The term "holographic reconstruction" refers to the optical reconstruction of an object formed by illuminating a hologram. The term "replay plane" is used herein to refer to a plane on space in which the holographic reconstruction is fully formed.

The terms "encoding", "writing" or "addressing" describe the process of providing a plurality of pixels of the SLM for a plurality of control values that each determine the modulation level of each pixel. Used. The pixels of the SLM may be configured to “display” a light modulation distribution in response to receiving a plurality of control values.

The term "light" is used herein in its broadest sense. Embodiments are equally applicable to visible light, infrared light and ultraviolet light, and any combination thereof.

Embodiments describe, as an example, an optical footprint that is monochromatic. In embodiments, the optical footprint is a multicolor optical footprint. In embodiments, a composite color light footprint is provided by combining a plurality of single color light footprints. In embodiments, a plurality of single color computer generated holograms may be used to form each composite color light footprint. This variety of wavelengths can increase throughput.

Embodiments describe 1D and 2D optical footprints only as examples. In other embodiments, the optical footprint is a 3D optical footprint. That is, in embodiments, each computer generated hologram forms a 3D holographic reconstruction.

Specific embodiments are described by way of example only with reference to the following drawings:
1 is a schematic diagram illustrating a reflective SLM that creates a holographic reconstruction on a screen.
2A shows a first iteration of an exemplary Gerchberg-Saxton type algorithm.
2B shows the second and subsequent iterations of the Gerchberg-Saxton type algorithm.
3 is a schematic of a reflective LCOS SLM.
4 illustrates a lidar system according to an embodiment.
5 illustrates a lidar system according to embodiments of the first group.
6 illustrates a scanning lidar system according to a first group of embodiments.
7A, 7B, 7C, and 7D illustrate exemplary first optical footprints and second optical footprints according to embodiments of the first group.
8 illustrates a lidar system using interleaved holograms according to a second group of embodiments.
9 shows an alternative configuration for interleaved holograms according to a second group of embodiments.
10 illustrates an interleaved hologram for scanning different areas of the scene in different directions according to the second group of embodiments.
FIG. 11 illustrates an interleaved hologram forming a first optical footprint having a first size and a second optical footprint having a second size smaller than the first size, according to an embodiment of the second group.
12 illustrates a feedback system for determining a plurality of computer generated holograms based on a signal received from a photo detector in accordance with a third group of embodiments.
13A, 13B, 13C, and 13D illustrate exemplary first and second scanning in accordance with a third group of embodiments.
14 shows an example of an angle magnification system.
15 illustrates a method of detecting and measuring an object according to embodiments.
In the drawings, like reference numerals refer to the same or similar parts.

The invention is not limited to the configurations described below, but extends to the full scope of the appended claims. That is, the present invention may be embodied in other forms and should not be construed as limited to the construction of the technical content presented for the purpose of explanation.

Terms in the singular form may include the plural form unless otherwise specified.

When described as structures formed above / below or above / below other structures, it should be construed to include cases in which structures are in contact with each other and cases in which third structures are disposed therebetween.

In describing a temporal relationship, when the time sequence of events is described, for example, "after", "following", "next", "before", and the like, the present disclosure shall describe continuous and discontinuous events unless otherwise specified. Should be considered to include. For example, the description should be considered to include discontinuous cases unless the description “just” “immediate” or “direct” is used.

Terms such as "first", "second", and the like may be used herein to describe various elements, but such elements are not limited by these terms. This term is only used to distinguish one element from another. For example, the first element may be referred to as a second element, and similarly, the second element may be referred to as a first element without departing from the scope of the appended claims.

Features of different configurations may be partly or wholly connected or combined with each other, and may interact with each other in various forms. Certain configurations may be performed independently of one another, or may be performed in conjunction with one another.

It has been found that holographic reconstructions of acceptable quality can be formed from "holograms" that contain only topological information associated with the original object. Such holographic recording may be referred to as phase-limited hologram. Embodiments are only illustratively related to phase-limited holograms. That is, in embodiments, the spatial light modulator applies only a phase delay distribution to incident light. In embodiments, the phase delay applied by each pixel is multiple levels. In other words, each pixel may be set to one of phase levels consisting of discrete numbers. In embodiments, the computer generated hologram is a Fourier transform on the object for reconstruction. In these embodiments, the hologram may be viewed as a Fourier domain representation or frequency domain representation for the object. 1 illustrates an embodiment using a reflective SLM to display a phase-limited Fourier hologram to produce a holographic reconstruction in a playback field.

For example, a light source 110 such as a laser or a laser diode is arranged to irradiate the SLM 140 through a collimating lens 111. The collimating lens causes the light to enter the plane wavefront as a whole on the SLM. The direction of the wavefront is slightly off-normal (eg, 2 ° or 3 ° away from the full perpendicular to the plane of the transparent layer). This arrangement allows the light from the light source to be reflected in the mirror of the rear face of the SLM and interact with the light modulation layer to form an exiting wavefront 112. The exit wavefront 112 is applied to an optical system that includes a Fourier transform lens 120 focused on the screen 125. The Fourier transform lens 120 receives a beam of phase modulated light emitted from the SLM and performs frequency-space conversion to generate a holographic reconstruction on the screen 125.

Light is incident across the phase-modulation layer (ie, array of phase modulation elements) of the SLM. Modulated light exiting the phase modulation layer is distributed across the reproduction field. In particular, in this type of holography, each pixel of the hologram is involved in the overall reconstruction. In other words, there is no one-to-one correlation between a particular point in the playback image and a particular phase modulation element.

In these embodiments, the position of the holographic reconstruction in space is determined by the optical power of the Fourier transform lens. In the embodiment shown in FIG. 1, the Fourier transform lens is a physical lens. That is, the Fourier transform lens is an optical Fourier transform lens and the Fourier transform is optically performed. However, in other embodiments, the Fourier transform is also performed computationally by including lensing data in the hologram data. That is, the hologram includes data representing a lens as well as data representing an object. In the art of computer-generated holograms, methods for calculating hologram data representing lenses are known. For example, a phase-limited holographic lens can be formed by calculating the phase delay caused at each point of the lens due to its refractive index and the spatially varying optical path length. For example, the optical path length at the center of the convex lens is greater than the optical path length at the edge of the lens. Amplitude-limited holographic lenses can be formed by Fresnel zone plates. In addition, in the field of computer-generated holograms, it is known how Fourier transforms can be performed without physical Fourier lenses by combining hologram data representing a lens with hologram data representing an object. In embodiments, lens data is combined with hologram data by simple vector addition.

Alternatively, in other embodiments, all Fourier transform lenses are omitted so that holographic reconstruction occurs in the far-field. In another embodiment, the hologram may include grating data, ie, data configured to perform the function of grating, such as beam steering. Again, methods of computing such hologram data in the field of computer generated holograms and combining them with hologram data representing objects are known. For example, phase-limited holographic gratings can be formed by modeling the phase delay caused by each point on the surface of the blazed grating. Amplitude-limited gratings can simply be superimposed on the amplitude-limited hologram to provide angular steering of the holographic reconstruction.

Fourier holograms in 2D images can be calculated in several ways, including using algorithms such as the Gerchberg-Saxton algorithm. The Gerchberg-Sexton algorithm can be used to derive the Fourier domain phase information from amplitude information (eg 2D images) in the spatial domain. That is, the phase information about the object may be "retrieved" from the intensity or amplitude limitation information in the spatial domain. Thus, the phase-limited Fourier transform for the object can be calculated.

In embodiments, computer-generated holograms are calculated from amplitude information using the Gerchberg-Sexton algorithm or its deformation algorithm. The Gerchberg-Saxton algorithm has a single Fourier transform of the intensity cross-sections of light beams I _A (x, y) and I _B (x, y) in each plane A and B, respectively. Consider interrelated situations. For a given intensity cross section, approximate values for Ψ _A (x, y) and Ψ _B (x, y) are obtained for the respective phase distributions in planes A and B. The Gerburg-Saxton algorithm finds a solution to this problem by following an iterative process.

The Gerchberg-Saxton algorithm repeatedly passes data sets (amplitude and phase) representing I _A (x, y) and I _B (x, y) between the spatial domain and the Fourier (spectrum or frequency) domain. (repeatedly transferring) Apply spatial and spectral constraints repeatedly. Spatial and spectral constraints are I _A (x, y) and l _B (x, y), respectively. Constraints in the spatial or spectral region are imposed on the amplitude of the data set. The phase information is obtained through a series of iterations.

In embodiments, the hologram is calculated using an algorithm based on the Gerchberg-Saxton algorithm as described in British Patent 2,498,170 or 2,501,112, which is incorporated herein in its entirety and incorporated herein.

According to embodiments, the Gerchberg-Saxton algorithm retrieves the phase information Ψ [u, v] of the Fourier transform of the data set that generates known amplitude information T [x, y]. Amplitude information T [x, y] represents a target image (eg a photograph). The phase information Ψ [u, v] is used to generate a holographic representation of the target image in the image plane.

Since amplitude and phase are essentially combined in a Fourier transform, the transformed magnitude (and phase) contains useful information about the accuracy of the calculated data set. Thus, the algorithm can repeatedly use feedback for both amplitude and phase information.

An example of an algorithm based on the Gerchberg-Sexton algorithm according to embodiments of the present invention is described below with reference to FIG. 2. This algorithm is iterative and convergent. The algorithm is configured to generate a hologram representing the input image. This algorithm can be used to determine amplitude limited holograms, phase limited holograms or fully complex holograms. The embodiments described herein relate only to generating phase limited holograms by way of example. Figure 2A shows the first iteration of an algorithm and highlights the importance of the algorithm. 2B shows the subsequent iteration of the algorithm.

For illustrative purposes, the amplitude and phase information are each considered individually, intrinsically combined to form a complex complex data set. With reference to FIG. 2A, the core of the algorithm may be considered to have an input comprising first complex data and an output comprising fourth complex data. The first complex data includes a first amplitude component 201 and a first phase component 203. The fourth complex data includes a fourth amplitude component 211 and a fourth phase component 213. In this example, the input image is two dimensional. Thus, the amplitude and phase information is a function of the spatial coordinates (x, y) and the (u, v) for the hologram field in the far-field image. That is, the amplitude and phase in each plane are the amplitude distribution and phase distribution in each plane. In this first iteration, the first amplitude component 201 is the input image 210 from which the hologram is calculated. In this first iteration, the first phase component 203 is just the random phase component 230 used as the starting point of the algorithm. Processing block 250 Fourier transforms the first complex data to form second complex data having a second amplitude component (not shown) and second phase information 205. In this example, the second amplitude component is discarded and replaced by the third amplitude component 207 by the processing block 252. In another example, processing block 252 performs different functions to generate third amplitude component 207. In this example, the third amplitude component 207 is a distribution representing the light source. The second phase component 205 is quantized by the processing block 254 to produce a third phase component 209. The third amplitude component 207 and the third phase component 209 form third complex data. The third complex data is input to processing block 256, which performs an Inverse Fourier Transform. Processing block 256 outputs fourth complex data having a fourth amplitude component 211 and a fourth phase component 213. The fourth complex data is used to form an input for the next iteration. That is, the fourth complex data of the n th iteration is used to form the first complex data of the (n + 1) th iteration.

2B shows the second and subsequent iterations of the algorithm. Processing block 250 includes first complex data having a first amplitude component 201 derived from a fourth amplitude component 211 of the previous iteration and a first phase component 213 corresponding to the fourth phase component of the previous iteration. Receive

In this example, the first amplitude component 201 is derived from the fourth amplitude component 211 of the previous iteration, as described below. Processing block 258 subtracts the input image 210 from the fourth amplitude component 211 of the previous iteration to form the fifth amplitude component 215. Processing block 260 scales the fifth amplitude component 215 by the gain factor a and subtracts it from the input image 210. This is represented mathematically by the following equation:

here:

F 'is the inverse Fourier transform;

F is a forward Fourier transform;

R is a play field;

T is the target image;

∠ angular information;

Ψ is a quantized version of angular information;

ε is the new target magnitude and ε> 0; And

α is the gain factor ˜1.

The gain element α can be fixed or variable. In the examples, the gain element α is determined based on the size and rate of the input target image data.

Processing blocks 250, 252, 254 and 256 have the function as described with reference to FIG. 2A. In the final iteration, the phase-limiting hologram Ψ (u, v) representing the input image 210 is output. It can be seen that the phase-limiting hologram Ψ (u, v) includes a phase distribution in the frequency or Fourier domain.

In another example, the second amplitude component is not discarded. Instead, the input image 210 is subtracted from the second amplitude component, and a multiple of that amplitude component is subtracted from the input image 210 to produce a third amplitude component 307. In another example, the fourth phase component is not fully fed back, for example, only partially fed back at a rate that changes over the last two iterations.

In embodiments, a real-time engine is provided that is arranged to receive image data and calculate holograms in real time using an algorithm. In embodiments, the image data is an image comprising a series of image frames. In other embodiments, the hologram is precomputed, stored in computer memory, and called as needed for display on the SLM. That is, in embodiments, a reservoir of some hologram is provided.

However, the embodiments merely relate to algorithms of the Fourier holography and Gerchberg-Saxton type by way of example. The present disclosure is equally applicable to Fresnel holography and holograms calculated by other techniques, such as based on the point cloud method.

The present disclosure can be implemented using any one of a number of different types of SLMs. The SLM can output spatially modulated light by reflecting or transmitting. In embodiments, the SLM is a liquid crystal on silicon, ie “LCOS”, SLM, but the present disclosure is not limited to this type of SLM.

The LCOS device can display a large array of phase confining elements that are within a small aperture. Small elements (typically about 10 microns or less) result in a practical diffraction angle (only a few degrees) so that the optical system does not require a very long optical path. Properly illuminating the small openings (sq square centimeters) of the LCOS SLM is easier than illuminating the openings of the larger liquid crystal device. In addition, the LCOS SLM has a large aperture ratio (since the circuit driving the pixels is buried under the mirror), so there is little dead-space between the pixels. This is an important issue for lowering optical noise in the reproduction field. Using a silicon backplane, the pixels are optically flattened, which is important for phase modulators.

By way of example only, a suitable LCOS SLM is described below with reference to FIG. 3. The LCOS element is formed using a single crystal silicon substrate 302. It has a two dimensional array of square planar aluminum electrodes 301 spaced by gap 301a and disposed on the top surface of the substrate. Each of the electrodes 301 may be formed through a circuit 302a embedded in the substrate 302. Each of the electrodes forms a respective planar mirror. An alignment layer 303 is disposed on the electrode array, and the liquid crystal layer 304 is disposed on the alignment layer 303. The second alignment layer 305 is disposed on the liquid crystal layer 304, and for example, the planar transparent layer 306 of glass is disposed in the second alignment layer 305. For example, a single transparent electrode 307 made of ITO is disposed between the transparent layer 306 and the second alignment layer 305.

Each of the square electrodes 301 forms a controllable phase modulation element 308, often referred to as a pixel, with a liquid crystal material interposed above and in the middle of the transparent electrode 307 region. The effective pixel area, or fill rate, is the percentage of total optically active pixels taking into account the spaces between the pixels 301a. By controlling the voltage for the transparent electrode 307 applied to each electrode 301, the properties of the liquid crystal material of the phase modulated element can be changed, thus providing a variable delay in incident light incident thereto. This adds phase-limited modulation to the wavefront while no amplitude effect occurs.

The above-described LCOS SLM outputs spatially modulated light by reflection, but the present disclosure is equally applicable to transmission LCOS SLM. Reflective LCOS SLMs have signal lines, gate lines, and transistors below the mirror surface, benefiting from high charge rates (typically over 90%) and high resolution. Another advantage of using reflective LCOS spatial light modulators is that the required liquid crystal layer thickness can be half that required than when transmissive devices are used. This greatly improves the switching speed of the liquid crystals (the main advantage for the projection of moving video images).

We have already disclosed various methods for providing improved image projection using the holographic techniques of this disclosure. The inventors have recognized that this hologram technique may be used to form the basis of an improved lidar system.

Specifically, the inventors have recognized that the technique can be used to write a sequence of computer generated holograms to a spatial light modulator that scans an optical footprint across a scene required for LIDAR. Preferably, the position of the optical footprint in the scene can be changed by changing the computer generated hologram. It is understood how the light detector can be synchronized with the light source and the spatial light modulator for light detection and ranging. The light has a first characteristic which means that it can be distinguished from other light received by the detector. The light is pulsed in time with the sequence of holograms. In embodiments, the first characteristic is amplitude modulated at the first frequency. However, light can be characterized in different ways. In embodiments, the first frequency is a radio frequency.

Embodiment of the first group

4 shows an embodiment that includes a spatial light modulator 410 disposed to direct light to scene 400 and a light detector 420 disposed to collect light reflected from the scene. The spatial light modulator 410 is configured to receive light from a light source (not shown) and output spatially modulated light according to a dynamically variable computer-generated hologram displayed on the spatial light modulator 410. Is placed. 4 illustrates first spatially modulated light 431 forming first optical footprint 451 in scene 400 in accordance with a first computer-generated hologram (not shown) represented on spatial light modulator 410. An output spatial light modulator 410 is shown. 4 also shows second spatial modulated light 432 forming a second optical footprint 461 in scene 400 in accordance with a second computer generated hologram (not shown) represented on spatial light modulator 410. It shows a spatial light modulator 410 to output.

The first computer generated hologram and the second computer generated hologram are displayed on the spatial light modulator at different times for scanning. The spatial light modulator receives a series of computer generated holograms from a hologram controller (not shown) to form the corresponding temporal sequence of optical footprints in the scene.

In some embodiments, the brightness of the optical footprint is substantially uniform over that area. In other embodiments, the brightness of the optical footprint changes with distance (ie, range) from the spatial light modulator. For example, the brightness of the optical footprint may increase with distance from the spatial light modulator. In one embodiment, a first optical footprint having a first brightness is formed at a first distance from the spatial light modulator, and a second footprint having a second brightness is formed at a second distance from the spatial light modulator, wherein The first distance is farther than the second distance, and the first brightness is brighter than the second brightness. The first optical footprint and the second optical footprint may be formed at substantially the same time or may be formed at different times. In one embodiment, the first optical footprint and the second optical footprint are a continuous series of optical footprints that are a temporal sequential arrangement (sequence) of the optical footprints in the scene.

Thus, a "LIDAR" system is provided, which is a light detection and surveying device arranged to scan a scene, the system comprising: a light source arranged to output light having a first characteristic; A spatial light modulator arranged to receive light from the light source and output spatially modulated light according to a computer generated hologram represented on the spatial light modulator; Arranged to output a plurality of computer-generated holograms to the spatial light modulator, each of the computer-generated holograms being arranged to form a corresponding optical footprint in the scene, and further to change the position of the optical footprint within the scene. A hologram controller disposed with; And a photo detector arranged to receive light having the first characteristic from the scene and to output a light response signal.

The hologram controller is arranged to move the optical footprint by changing the hologram pattern displayed on the spatial light modulator. In embodiments, the plurality of computer generated holograms are first computer generated holograms arranged to form a first optical footprint at a first location in a scene and a second computer arranged to form a second optical footprint at a second location A generation hologram, wherein the output of the second computer generated hologram appears immediately after the output of the first computer generated hologram.

Lidar (LIDAR) systems are known to use moving optics, such as rotating prisms, for optical scanning. However, such a system has significant disadvantages since it requires moving parts. The holographic lidar system disclosed herein does not require moving optics for light scanning. Instead, moving the optical footprint is provided by computing and manipulating the hologram with a computer. Furthermore, in the field of computer generated holograms, how to calculate hologram data indicative of gratings for beam steering and to couple the beam to hologram data indicative of an object (e.g., optical footprint). There is a known method. The characteristics of the holographic grating, such as periodicity, can be changed dynamically to direct light to the desired location in the scene.

A lidar system using a rotating prism performs continuous scanning in one direction by continuously rotating the prism at a predetermined speed. In contrast, the holographic lidar system disclosed herein allows for dynamic rearrangement of optical footprints within a scene without limitation. In particular, the optical footprint can be moved from one position of the scene to any other position of the scene without illuminating the intermediate positions. In this regard, the optical footprint may be momentarily jumped from one location of the scene to any other location of the scene. In embodiments, the first position is spatially separated from the second position. This provides a more flexible scan, unlike a rotating prism system that requires rotating the prism for positional movement. Thus, the holographic lidar system according to the present disclosure provides more flexible scanning and faster dynamic scanning. However, it can be understood that the present system is equally appropriate even when the first position is substantially adjacent to the second position. 5 illustrates an embodiment in which the first optical footprint 551 and the second optical footprint 561 are substantially adjacent.

6 illustrates an embodiment in which the optical footprint 651 is moved within the scene to illuminate a continuous area of the scene. That is, in an embodiment, the optical footprint is continuously repositioned to scan the optical footprint in the scene. 6 shows a continuous scan, the system is equally suitable for providing a discontinuous scan.

The inventors also recognized that the computer computed properties of the holographic system can be used to instantaneously change the properties of the optical footprint to provide improved scanning. In embodiments, the first optical footprint has a first area and the second optical footprint has a second area, and the first area is not the same as the second area.

FIG. 7A shows a first optical footprint 751 and a second optical footprint 761 in scene 700. The second optical footprint 761 has an area smaller than that of the first optical footprint 751. The system may be arranged to scan the first area 750 of the scene 700 into the first optical footprint 751 and the second area 760 into the second optical footprint 761. The second optical footprint 761 may be formed immediately after the first optical footprint 751 and vice versa. The smaller the optical footprint, the higher the spatial resolution of the system. Thus, the spatial resolution of scanning can be dynamically controlled by the holographic lidar system of the present disclosure. For example, in embodiments, it may be advantageous to change the resolution of scanning.

If the optical footprint size is reduced, it becomes brighter because the projection method is holographic (all pixels in the hologram act on every point of the reconstruction). This may improve the signal to noise ratio or increase the maximum range (available distance) of the device. In one embodiment, higher resolution scanning is performed in one or more areas of the scene, and lower resolution scanning is performed in another one or more areas of the scene. As one example, the system is arranged to scan a road with a first optical footprint and to scan a curb with a second optical footprint, wherein the first optical footprint is larger than the second optical footprint. The curb is thus scanned at a higher resolution than, for example, the front of the vehicle. This is due to the fact that it may be necessary to find out if there is a vehicle ahead and its distance apart, but it may not be necessary for the vehicle to determine the width of the vehicle. Scanning the curb at higher resolutions provides positional accuracy. Thus, in some embodiments, the center of the scene is scanned at a relatively low resolution, and one or more perimeters of the scene are scanned at a relatively high resolution. That is, scanning more than one perimeter of a scene has a higher resolution than scanning the center of the scene.

In other embodiments, the hologram system is used to provide footprints of different shapes. 7B illustrates an embodiment in which the first optical footprint 752 has a different shape than the second optical footprint 762. That is, in embodiments, the first optical footprint has a first shape and the second optical footprint has a second shape, where the first shape is different from the second shape. It may be advantageous to use footprints with different shapes to probe different areas of the scene or different objects in the scene. Thus, a more flexible lidar system is provided.

In embodiments, the hologram system is used to rotate the optical footprint. 7C illustrates an embodiment in which the first optical footprint 753 and the second optical footprint 763 have the same shape but are oriented differently. That is, in embodiments, the first optical footprint has a shape having a first orientation and the second optical footprint has a shape having a second orientation, and the first orientation is different from the second orientation. For example, accurate location information can be obtained by scanning in two different directions. In other examples, the optical response signal can be increased or optimized by changing the direction of the optical footprint.

In embodiments, the shape is a substantially one-dimensional shape. For example, the optical footprint may have a slit or linear shape. 7D illustrates an embodiment in which the first optical footprint 754 is perpendicular to the second optical footprint 764. One-dimensional footprints provide one-dimensional scanning, which is advantageous, for example, to quickly scan across the scene to see if any objects are present in the scene. One-dimensional scanning of the first area in the scene in the first direction and one-dimensional scanning of the second area in the scene in the orthogonal direction can be advantageous. That is, in an embodiment, the first orientation is perpendicular to the second orientation.

Embodiment of Group 2—Interleaved Scanning

8 illustrates an embodiment that includes a spatial light modulator 810 disposed to direct light to a scene 800 and a light detector 820 disposed to collect light reflected from the scene. The spatial light modulator 810 is arranged to receive light from a light source (not shown) and to output spatially modulated light according to the dynamically variable computer generated hologram represented on the spatial light modulator 810. 8 outputs first spatial modulated light 831 forming a first optical footprint 851 in scene 800 according to a first computer generated hologram (not shown) represented on spatial light modulator 810. FIG. 8 also illustrates a second optical footprint in scene 800 in accordance with a second computer generated hologram (not shown) represented on spatial light modulator 810. Illustrates spatial light modulator 810 for outputting second spatial modulated light 832 forming 861. The first computer generated hologram and the second computer generated hologram are displayed on the spatial light modulator at different times to provide scanning. The spatial light modulator is a computer-generated hologram from a hologram controller (not shown) to form temporal sequences of corresponding optical footprints within a scene that includes a first optical footprint 851 and a second optical footprint 861. Sequences 891, 895, 892, 896, 893, 897, 894.

8 illustrates a plurality of first computer generated holograms 891, arranged to form a plurality of first optical footprints including a first optical footprint 851 in a first area 850 of scene 800. 892 and 893 are shown. 8 also shows a plurality of second computer generated holograms 895 arranged to form a plurality of second optical footprints including a second optical footprint 861 within the second area 860 of the scene 800. 896, 897).

Second optical footprints comprising a second optical footprint 861 and a plurality of second computer generated holograms 895, 896 and 897 are shown in hatched form for illustrative purposes only to indicate that they correspond. It became. However, it should be noted that what is displayed on the spatial light modulator is not simply optically translated into the scene. Each computer-generated hologram is a diffraction pattern, which recreates the corresponding optical footprint in the scene by interference. There is no one-to-one correlation between the points in the hologram and the points in the scene. Each point in the hologram contributes to every point in the corresponding optical footprint. Likewise, a first optical footprint comprising a first optical footprint 851 and a plurality of first computer generated holograms 891, 892 and 893 is illustrated to indicate that they correspond to indicate that they correspond. It is shown without hatching for technical reasons.

The plurality of first computer generated holograms 891, 892, 893 are arranged to provide a first scanning 850 of the scene 800 in a first direction 880. Computer-generated hologram 883 corresponds to first optical footprint 851. 895, 896, 897 are arranged to provide a second scanning 860 of scene 800 in a second direction 885. . Computer generated hologram 897 corresponds to second optical footprint 861. There are only three computer generated holograms each, the present invention involves using any number of computer generated holograms in each scan.

Thus, in embodiments, the plurality of computer generated holograms may comprise a plurality of first computer generated holograms arranged to provide first scanning in the scene and a plurality of second computer generated holograms arranged to provide second scanning in the scene. It can be understood to include. 8 shows, by way of example only, a first scanning and a second scanning in a different direction. In other embodiments, the first scanning and the second scanning scan in the same direction.

8 illustrates a hologram of a plurality of first computer generated holograms and a plurality of second computer generated holograms alternately output to the spatial light modulator 810. That is, in embodiments, the plurality of first computer generated holograms and the plurality of second computer generated holograms are interleaved. However, the present disclosure includes any placement scheme for interlacing. For example, FIG. 9 illustrates another embodiment in which two holograms of the plurality of first computer generated holograms 991, 992, 993, 994 are interleaved with holograms of one of the plurality of second computer generated holograms 995, 996. Shows.

In embodiments comprising the embodiments shown in FIGS. 8 and 9, the first scanning is a scanning of the first area of the scene and the second scanning is a scanning of the second area of the scene, where the second area is the first It is spatially separated from the area. It will be appreciated that the plurality of computer generated holograms are arranged to scan the first and second regions by moving the spatially modulated light back and forth between the first and second regions. Again, as mentioned above, LiDAR systems based on scanning optics can't achieve this feature, allowing faster scanning of spatially separated areas of the scene.

10 illustrates a scene 1000 that includes a first region 1050 and a second region 1060. The plurality of first computer-generated holograms 1091, 1092, 1093 are arranged to scan the first optical footprint 1051 in the first direction 1080 within the first region 1050. The plurality of second computer generated holograms 1095, 1096, 1097 are arranged to scan the second optical footprint 1061 in the second direction 1085 in the second region 1060. Thus, in an embodiment, the first scanning is scanning the first area in the scene in the first direction and the second scanning is scanning the second area in the scene in the second direction. In embodiments, the second scanning may also be scanning the first area. In these embodiments, the second scanning is performed in the same direction as the first scanning.

According to embodiments, the first scanning, which is relatively low resolution, is interleaved with the second scanning, which is high resolution scanning. Again, the smaller the optical footprint, the higher the spatial resolution. 11 illustrates an embodiment in which the second footprint 1161 has a smaller area than the first footprint 1051. Thus, in embodiments, the plurality of first computer generated holograms are disposed to form a first footprint having a first area and the plurality of second computer generated holograms form a second optical footprint having a second area. And the first area is not the same as the second area.

In embodiments, the first optical footprint has a substantially one-dimensional shape extending in the second direction, and the second optical footprint has a substantially one-dimensional shape extending in the first direction.

The first and second scanning interleaved (cross-batch co-operation) may relate to the same or different areas of the scene. Area of the scene by simultaneously scanning the same area of the scene using different optical footprints (e.g., the footprint of the first scan that corresponds to a finer or higher resolution scan and the footprint of the second scan that corresponds to a coarse or lower resolution scan) It can provide different information about. The same or different footprints can be used to simultaneously scan different areas of the scene to obtain information about different areas of the scene. Since the first and second scanning are interleaved (crossed) and performed simultaneously, the information obtained by the two scannings relates to the scene at substantially the same point in time.

According to embodiments, the first scanning may comprise a stochastic scan, which may be used to scan an optical footprint that is randomly moved around the scene (eg, to another area around the vehicle). To project. If a feature (feature) in the scene is identified from a stochastic scan (eg, from an optical response signal for the first scanning) or otherwise, includes the identified feature (eg, at a higher resolution). The second scanning may be performed on the region. In embodiments, the stochastic scan is continuous and one or more second scanning (eg, of higher resolution) is interleaved with the stochastic scan. In particular, the high resolution second scanning may be performed simultaneously with the stochastic scan, as described above with reference to FIGS. 8 to 11. Thus, the stochastic scan can be performed continuously, and a second scanning with a limited duration can be attempted and interleaved with the stochastic scan as needed. For example, when a feature is detected within a particular area, a second high resolution scan for that particular area may be added and interleaved with the stochastic scan and then removed when the high resolution scan is complete. Thus, new target objects are continuously identified by successive stochastic scans, and details of such identified target objects are continuously obtained by the second scan. In alternative embodiments, the second scanning may be performed instead of the stochastic scan (ie, the first and second scanning are not in parallel). In this case, the first scanning and the second scanning are alternately performed.

Embodiment of Group 3-Intelligent Scanning

Embodiments provide a feedback system that uses the results of the first scanning to determine a computer generated hologram for the second scanning. Determining the computer-generated hologram for the second scanning may include selecting a hologram from a reservoir of holograms or calculating a hologram.

FIG. 12 illustrates an embodiment that includes a spatial light modulator 1210 arranged to direct light to a scene 1200 and a light detector 1220 disposed to collect light reflected from the scene. Spatial light modulator 1210 is arranged to receive light from a light source (not shown) and to output spatially modulated light according to the dynamically variable computer generated hologram represented on spatial light modulator 1210. 12 outputs first spatial modulated light 1231 to form first optical footprint 1251 in scene 1200 according to a first computer generated hologram (not shown) represented on spatial light modulator 1210. A spatial light modulator 1210 is shown.

12 shows a light detector 1220 that receives light 1241 reflected from an area of scene 1200 in which first optical footprint 1251 is illuminated. For example, the light can be reflected from objects in the scene. In response to receiving reflected light 1241, photodetector 1220 outputs light response signal 1274. The hologram controller 1270 is arranged to receive the optical response signal 1274 and determine a plurality of second computer generated holograms. The hologram controller 1270 outputs the hologram data 1272 including the plurality of second computer generated holograms to the spatial light modulator 1210.

Hologram controller 1270 may evaluate the properties of optical response signal 1274 to determine a plurality of second computer generated holograms. In an embodiment, hologram controller 1270 determines whether optical response signal 1274 indicates that the object is within the area scanned into the first optical footprint. In some embodiments, the property of optical response signal 1274 is the maximum (or peak) intensity or average intensity of optical response signal 1274. In other embodiments, the property of the optical response signal 1274 is the intensity change of the optical response signal 1274 or the rate of change of the intensity of the optical response signal 1274. The property of the optical response signal 1274 may be that the intensity of the optical response signal is any property of the optical response signal 1274 or any features of the optical response signal 1274, which is true for the scanned area. Alternatively, information about any scanned object may be provided. For example, the hologram controller 1270 may determine whether the magnitude of the optical response signal 1274 exceeds a threshold. For example, in embodiments, the hologram controller 1270 determines that an object is present in the first area scanned with the first optical footprint 1251 and is arranged to scan the first area again at high resolution. 2 Determine the computer generated hologram. For example, in other embodiments, hologram controller 1270 determines whether an object exists in a first area scanned with first optical footprint 1251, and uses second optical footprint 1261 to display the scene. Determine a plurality of second computer generated holograms arranged to scan the second area. For example, in another embodiment, hologram controller 1270 determines whether the optical response signal is determinable (eg, relatively noisy) and rescans the same area of the scene, just in the other direction. Determine a plurality of second computer generated holograms arranged to

In response to each computer generated hologram of the plurality of second computer generated holograms, a corresponding second optical footprint 1261 is formed in the scene 1200. The second optical foot print 1261 may be scanned within the scene 1200 as described above. Spatial light modulator 1210 includes a plurality of second computer generated holograms from hologram controller 1270 to form a temporal sequence of corresponding optical footprints, including second optical footprint 1261, within scene 1200. Receive

Thus, in embodiments, the plurality of computer generated holograms comprises a plurality of first computer generated holograms arranged to provide a first scanning in the scene, wherein the hologram controller receives an optical response signal in response to the first scanning. And determine a plurality of second computer-generated holograms based on attributes of an optical response signal in response to the first scanning. In embodiments, the plurality of second computer generated holograms are arranged to provide a second scanning in the scene.

FIG. 13A illustrates an embodiment in which the first scanning scans the first area 1350 of the scene 1300 in the first optical footprint 1351 in the first direction 1380. The second scanning corresponds to the plurality of second computer-generated holograms, and may scan the first area 1350 or the second area 1360 of the scene 1300.

FIG. 13B illustrates an embodiment in which the first scanning scans the first area of the scene and the second scanning scans the second area of the scene, the second area being spatially separated from the first area.

13C shows an embodiment where the first scanning is scanning the first area of the scene in a first direction and the second scanning is scanning the first area of the scene in a second direction. In embodiments, the second scanning is performed using a second optical footprint having a different size, shape, and / or orientation than the first optical footprint.

13D illustrates that the plurality of first computer generated holograms are arranged to form a first optical footprint having a first area and the plurality of second computer generated holograms are arranged to form a second optical footprint having a second area. An embodiment is shown, where the first region is not the same as the second region.

In embodiments, the first area of the scene scanned by the first scanning may be the same, partially, adjacent or spatially separate from the second area of the scene scanned by the second scanning.

Modifications to Examples of All Groups

In embodiments, the first optical footprint has a substantially one-dimensional shape extending in the second direction, and the second optical footprint has a substantially one-dimensional shape extending in the first direction.

In embodiments, the spatial light modulator is a phase limited spatial light modulator. These embodiments have an advantage because no optical energy is lost by modulating the amplitude. Thus, an efficient holographic projection system is provided. However, the present invention can be implemented equally on an amplitude limited spatial light modulator or an amplitude and phase modulator. It can be understood that the hologram will correspond to being phase limited, amplitude limited or fully complex.

Embodiments include an angular magnification system for increasing the field of view of the system. 14 illustrates an angle magnification system 1425 arranged to receive spatially modulated light at a first angle from spatial light modulator 1410. The angle magnification system 1425 outputs spatially modulated light at a second angle greater than the first angle, illuminating the scene. FIG. 14 shows that the angle magnification system 1425 is arranged to receive light 1422 at a first angle and output light 1424 at a second angle that is greater than the first angle. The angle magnification system can be viewed as enlarging the light angle of the spatially modulated light. That is, in embodiments, the lidar system further includes an angle magnification system arranged to magnify the angular deflection of the spatially modulated light from the spatial light modulator.

In embodiments, angular magnification is by refraction. That is, in embodiments, the angle magnification system is arranged to refract the spatially modulated light. In embodiments, the angle magnification system is arranged to receive spatially modulated light at a first angle and output spatially modulated light at a second angle greater than the first angle.

In embodiments, the light is pulsed. Thus, in embodiments, the system is configured such that any reflected signal is received by the detector before the next light footprint is irradiated to the scene. Thus, the system can process any return signal before the next optical footprint and can not be confused with the footprint that generates the return signal. Those skilled in the art will understand how to synchronize light sources, hologram controllers, spatial light modulators, light detectors and any necessary processors to provide the functionality, and details thereof are not presented herein.

Each optical footprint is formed using a corresponding computer generated hologram. Each computer generated hologram is displayed on the spatial light modulator in accordance with the hologram data provided to the spatial light modulator. Each computer-generated hologram may consist of different data components. The data provides instructions for a spatial light modulator that individually addresses each light modulating pixels of the spatial light modulator. In particular, the data may provide instructions for each pixel with respect to the degree of modulation of the light. In embodiments, the computer generated hologram includes first hologram data defining the size and shape of the optical footprint and second hologram data defining the location of the optical footprint in the scene. The first hologram data may include hologram data that provides an optical effect. In embodiments, the first hologram data includes a lensing function. As described above, the second hologram data provides variable beam steering information. In embodiments, the second hologram data includes a grating function.

FIG. 15 illustrates an embodiment that includes a processor 1570 in communication with a spatial light modulator 1510 and a light detector 1520. In operation, the processor 1570 is arranged to receive an optical response signal from the photo detector 1520 and to receive synchronization information 1572 from the spatial light modulator 1510. The spatial light modulator 1510 is arranged to output spatially modulated light 1531 that forms an optical footprint (not shown) at one location in the scene. The object 1505 at one location in the scene reflects the spatially modulated light 1531 and the reflected light 1541 is detected by the photo detector 1520. The photo detector 1520 is configured to have a field of view that includes the scene.

For example, the photo detector 1520 may be a single photodetector (eg, a single photodiode) or an array of photodetection elements (eg, one dimensional or according to an optical footprint and / or design requirements). Two-dimensional photodiode array). As noted above, synchronization and light pulsed between the components of the system are spatially modulated as the air-modulated light moves from the spatial light modulator 1510 through the object 1505 to the photo detector 1520. It is used to determine a time of flight for light. Measuring this flight time can be used to determine the straight line distance 1576 from the spatial light modulator 1510 to the object 1505. As such, a light detection and range lidar (LIDAR) system is provided. In embodiments, the lidar transmitter includes a spatial light modulator 1510 and the lidar receiver includes a light detector 1520, at least one of which is a lamp unit or portable device, such as a head lamp unit of a vehicle. Or may be located within the vehicle. The processor 1570 may be located with a lidar transmitter and / or lidar detector or may be remotely located.

In embodiments, the light source is a laser. In embodiments, the light detector is a photodetector. In embodiments, a vehicle is provided that includes the present lidar system.

In embodiments, the laser light coming from the light source may be modulated with a code unique to the lidar system. Such coding may be used to avoid interference or confusion associated with other lidar systems (eg, systems in other vehicles on the road). In such embodiments, the lidar receiver searches for the coded in the received light and processes only the received light modulated with the corresponding code. For example, binary evolution of light amplitude with a unique binary pattern can be performed to provide a unique code (e.g., by switching the light source on and off with a predetermined code or pattern). Other types of modulation or encoding of laser light may be performed.

In some embodiments, two or more light sources may be used. For example, two or more lasers having different wavelengths (eg, wavelengths in the IR range) may be included in the LiDAR system and may be used at different times to provide light to the SLM. The laser used as the light source, and thus the wavelength of the light used to form the footprint of the light, may be changed depending on the ambient conditions to provide improved light penetration, such as when fog or other bad weather conditions are detected.

In embodiments, the lidar system may perform scanning at different distance ranges. For example, in embodiments, the hologram controller of the lidar system may provide holograms to the SLM in different time sequences to scan the scene for each distance range. In particular, the hologram data provided to the SLM can be used to adjust the lensing function corresponding to the Fourier transform lens used to reconstruct the computer generated hologram (e.g., as described above), or the corresponding lens data in the lens data. By changing) the optical footprint can be determined to be concentrated in the reproduction plane corresponding to the required distance or range. In other embodiments, the physical Fourier transform lens can be selected to focus the optical footprint on a reproduction plane corresponding to the required distance or range. Thus, in embodiments, it can be seen that a parameter or element associated with an optical footprint or a plurality of computer generated holograms forming the optical footprint is determined based on a distance range. In particular, the determination is such that the optical footprint is focused at a distance corresponding to the distance range.

The appropriate lensing function / data or physical Fourier transform lens for a particular range can be determined in response to the range selection signal. For example, the range selection signal may be provided manually by the user, or may be automatically provided when a predetermined condition is detected. Selecting the range may be based on vehicle speed, traffic density or other driving factors or conditions. If the vehicle is traveling at higher speeds, it may be desirable to select longer distance scanning. For example, long distances may be preferred for highway driving, and short distances may be preferable for urban driving with heavy traffic. Thus, in embodiments, the range of distances is to be selected based on the received signal. In embodiments, the distance range may be vehicle speed; Ambient conditions; Weather conditions; It is determined based on one or more of the traffic conditions and other driving parameters.

Although embodiments of the first, second, and third groups have been disclosed approximately and individually, any features for any embodiment or group of embodiments may be any other feature or for any embodiment or group of embodiments, or It can be combined with a combination of features. That is, all possible combinations and substitutions of the features described in this disclosure can be considered.

In embodiments, the first optical footprint may be formed of light of a first wavelength and the second optical footprint may be formed of light of a second wavelength. In embodiments, the first scanning may be performed using light of the first wavelength and the second scanning may be performed using light of the second wavelength. In embodiments, the first and second wavelengths are different index visible light. In embodiments, one or both of the first and second wavelengths are infrared and of different wavelengths.

In embodiments, the system includes a first spatial light modulator for forming a first optical footprint and a second spatial light modulator for forming a second optical footprint. In other embodiments, a single spatial light modulator is used. For example, in embodiments, the first region of the spatial light modulator is assigned to the hologram forming the first optical footprint, and the second region of the spatial light modulator is assigned to the hologram forming the second optical footprint. .

The quality of holographic reconstruction can be influenced by the so-called zero-order problem caused by the diffraction properties using a pixelated spatial light modulator. Such zero order light may be considered “noise” and includes, for example, specularly reflected light (ie, non diffracted light) and other unwanted light from the SLM.

In the example of Fourier holography, this “noise” is focused on the Fourier lens' focus, thereby causing a bright spot in the center of the holographic reconstruction, known as the “DC spot”. Zero-order light can simply be shielded, but this means that the bright spot should be replaced by the dark spot. Embodiments include an angle selection filter that removes only parallel rays of order 0. Embodiments also include a method for managing the zero-order disclosed in European Patent No. 2,030,072, which is incorporated herein by reference in its entirety. In other embodiments, the spatial light modulator is illuminated with divergent light, whereby the diffracted light forming the optical footfurt is focused at the reproduction plane but the zero order light (not diffracted) continues to diverge. Thus, zero shading is effectively dispersed.

Embodiments described herein include displaying one hologram per frame on a spatial light modulator, but the present disclosure is by no means limited thereto, and two or more holograms may be displayed on the SLM at one time. For example, embodiments implement a "tiling" technique, where the surface area of the SLM is further divided into multiple tiles, each tile being set to a phase distribution that is similar or identical to that of the original tile. . Thus, each tile has a smaller surface area than if all SLMs of the SLM were used in one large phase pattern. The fewer the number of frequency components in the tile, the more the reconstructed pixels are separated when the image is created. The image is generated within the zeroth diffraction order, and the first and higher orders are preferably placed far enough so that they do not overlap the image and can be blocked through a spatial filter.

As mentioned above, the holographic reconstruction (with or without tiling) generated by this method includes spots that form an image pixel. The greater the number of tiles used, the fewer these points. Applying the example of Fourier transform of infinite sine wave, a single frequency is generated. This is the optimal output. In practice, this corresponds to a single cycle input of a sine wave where zero values extend in positive and negative directions from the end nodes of the sine wave to infinity, when only one tile is used. Instead of a single frequency generated from the Fourier transform, the main frequency component is produced as series components of adjacent frequencies on either side. By using tiling, the size of these adjacent frequency components is reduced and, as a direct result, less interference (both constructive and destructive) between adjacent image pixels results in improved image quality. Preferably, embodiments use pieces of a tile, but each tile is an entire tile.

The methods and processes described herein can be implemented on a computer readable medium. The term “computer readable medium” includes media configured to temporarily or permanently store data, such as random access memory (RAM), read-only memory (ROM), buffer memory, flash memory, and cache memory. The term "computer-readable medium" also includes any medium or combination of media that can store instructions for execution by a machine, such as when executed by one or more processors, cause the instructions to execute a machine. And may be capable of performing one or more of the methodologies described herein in whole or in part.

The term "computer readable medium" also includes cloud-based storage systems. The term “computer readable medium” is, but is not limited to, one or more real and non-transitory data storage in a solid state memory chip, an optical disk, a magnetic disk, or any suitable combination thereof. Include them. In some embodiments, instructions for execution can be conveyed by a transmission medium. Examples of such transmission media include transitory media (e.g., radio signals carrying commands).

Various modifications and variations can be made without departing from the scope of the appended claims, which will be apparent to those skilled in the art. The present disclosure is intended to embrace all such alterations and modifications as come within the scope of the appended claims and their equivalents.

The following items are disclosed.

Item 1. A lidar system for light detection and surveying arranged to scan a scene, the system comprising:

A light source arranged to output light having a first characteristic;

A spatial light modulator ("SLM") arranged to receive light from a light source, said spatial light modulator ("SLM") comprising: a spatial light modulator arranged to output spatially modulated light according to a computer-generated hologram represented on said spatial light modulator;

A hologram controller arranged to output a plurality of computer generated holograms to the spatial light modulator, wherein each computer generated hologram is arranged to form a corresponding light footprint within the scene, the hologram controller in the scene; A hologram controller disposed to change the position of the optical footprint in the apparatus; And

A light detector arranged to receive light having a first characteristic from the scene and to output a light response signal.

Item 2. The lidar system defined in item 1, wherein the plurality of computer generated holograms comprise a plurality of first computer generated holograms arranged to provide first scanning within the scene, wherein the hologram controller A lidar system that receives the optical response signal in response to a first scanning and determines a plurality of second computer-generated holograms based on attributes of the optical response in response to the first scanning.

Item 3. The lidar system defined in item 2, wherein the plurality of second computer-generated holograms are arranged to provide a second scanning within the scene.

Item 4. The lidar system defined in item 3, wherein the first scanning is scanning of a first area of the scene and the second scanning is scanning of a second area of the scene.

Item 5. The lidar system defined in item 3 or 4, wherein the first scanning is scanning a first area of the scene in a first direction, and the second scanning is a first of the scene. A lidar system for scanning an area in a second direction.

Item 6. The lidar system as defined in any one of items 2 to 5, wherein the plurality of first computer-generated holograms are arranged to form a first optical footprint having a first area, the plurality of The second computer-generated hologram is arranged to form a second optical footprint having a second area, wherein the first area and the second area are different areas.

Item 7. The lidar system defined in item 6, wherein the first optical footprint has a substantially one-dimensional shape extending in a second direction, wherein the second optical footprint extends in a first direction Lidar system having a substantially one-dimensional shape.

Item 8. The lidar system defined in item 1, wherein the plurality of computer generated holograms are arranged to form a first optical footprint at a first location in the scene and a second in the scene. A second computer-generated hologram disposed to form a second optical footprint at a position, wherein the output of the second computer-generated hologram is immediately following the output of the first computer-generated hologram.

Item 9. The lidar system as defined in item 8, wherein the first position is spatially separated from the second position.

Item 10. A lidar system as defined in item 9, wherein the first position is substantially adjacent to the second position.

Item 11. The lidar system as defined in any of items 8 to 10, wherein the optical footprint is continuously repositioned to scan the optical footprint within the scene.

Item 12. The lidar system as defined in any of items 8 to 11, wherein the first optical footprint has a first area and the second optical footprint has a second area. Lidar system in which the first region and the second region is a different region.

Item 13. The lidar system defined in any one of items 8 to 12, wherein the first optical footprint has a first shape and the second optical footprint has a second shape, The first shape is a lidar system different from the second shape.

Item 14. The lidar system as defined in any of items 8 to 13, wherein the first optical footprint has a shape having a first orientation and the second optical footprint has a second orientation. A lidar system having a shape, wherein the first orientation and the second orientation are in different directions.

Item 15. A lidar system as defined in item 14, wherein the shape is a substantially one-dimensional shape.

Item 16. The lidar system as defined in items 14-15, wherein the first orientation is perpendicular to the second orientation.

Item 17. The lidar system defined in item 1, wherein the plurality of computer generated holograms are configured to provide a plurality of first computer generated holograms arranged to provide a first scanning in the scene and a second scanning in the scene. Lidar system including a plurality of second computer-generated holograms disposed

Item 18. A lidar system as defined in item 17, wherein the plurality of first computer generated holograms and the plurality of second computer generated holograms are interleaved.

Item 19. The lidar system defined in item 17 or 18, wherein the first scanning is scanning of a first area of the scene and the second scanning is scanning of a second area of the scene. Lidar system.

Item 20. A lidar system as defined in item 19, wherein the second region is spatially separated from the first region.

Item 21. The lidar system as defined in item 19 or 20, wherein the plurality of computer generated holograms move the space modulated light back and forth between the first area and the second area. And a lidar system arranged to scan the second area.

Item 22. The lidar system defined in any of items 17 to 21, wherein the plurality of first computer-generated holograms arranged to perform the first scanning comprises a plurality of random locations within the scene. A lidar system arranged to form an optical footprint in the fields.

Clause 23. A lidar system as defined in clause 22, wherein the first scanning is a continuous lidar system.

Item 24. A lidar system as defined in item 22 or 23, wherein the plurality of second computer-generated holograms are arranged to perform a second scanning of an area within the scene.

Item 25. A lidar system as defined in item 24, wherein the lidar system determines the area based on attributes of an optical response signal in response to the first scanning.

Item 26. The lidar system as defined in any one of items 17 to 25, wherein the first scanning is scanning in a first direction and the second scanning is scanning in a second direction. system.

Item 27. The lidar system defined in any of items 17 to 26, wherein the plurality of first computer-generated holograms are arranged to form a first optical footprint having a first area and the plurality of The second computer-generated hologram is arranged to form a second optical footprint having a second area, the first area and the second area being different liars.

Item 28. The lidar system defined in item 27, wherein the first optical footprint has a substantially one-dimensional shape and extends in a second direction, wherein the second optical footprint has a substantially one-dimensional shape Lidar system extending in the first direction.

Item 29. The lidar system as defined in items 1 to 28, wherein each computer-generated hologram is a phase limited hologram.

Item 30. The lidar system as defined in any of clauses 1 to 29, wherein the spatially modulated light output by the spatial light modulator is a li encoded to a code unique to the lidar system. system.

Item 31. A lidar system as defined in item 30, wherein the spatially modulated light output by the spatial light modulator is encoded by modulating an optical amplitude.

Item 32. A lidar system as defined in any of items 1 to 31, comprising a first light source and a second light source configured to output light of different wavelengths to the spatial light modulator.

Item 33. The lidar system as defined in item 32, wherein the first light source and the second light source are selected based on ambient conditions.

Item 34. The lidar system as defined in any of items 1 to 33, wherein the optical footprint or parameters or elements relating to the plurality of computer-generated holograms forming the optical footprint are received. Lidar system determined based on signal.

Item 35. The lidar system defined in item 34, wherein the received signal is a vehicle speed; Ambient conditions; Climatic conditions; Lidar system that provides an indication of one or more of traffic conditions and other driving parameters.

Item 36. The lidar system as defined in any of items 1 to 35, wherein a parameter or element relating to the optical footprint or the plurality of computer-generated holograms forming the optical footprint is a distance range. Lidar system determined based on.

Item 37. The lidar system defined in item 36, wherein the parameters relating to the optical footprint or the plurality of computer-generated holograms forming the optical footprint focus an optical footprint at a distance corresponding to a distance range. Lidar system that is determined to have.

Item 38. The lidar system defined in item 36 or item 37, wherein the range of distances is determined by vehicle speed; Ambient conditions; Climatic conditions; Lidar system selected based on one or more of traffic conditions and other driving parameters.

Item 39. A lidar system as defined in any of items 1 to 38, further comprising an angle enlargement system arranged to enlarge the angle deflection of the spatially modulated light coming from the spatial light modulator. system.

Item 40. The lidar system as defined in item 39, wherein the angular magnification system is arranged to refract the spatially modulated light.

Item 41. The lidar system defined in item 39 or 40, wherein the angle expanding system is arranged to receive the spatially modulated light at a first angle and output the spatially modulated light at a second angle; And the second angle is greater than the first angle.

Clause 42. A lidar system as defined in any of clauses 1 to 41, wherein the first characteristic is amplitude modulated at a first frequency.

Item 43. The lidar system as defined in any of items 1 to 42, wherein the light is pulsed.

Item 44. The lidar system as defined in any of items 1 to 31, wherein the spatial light modulator is a spatial light modulator that is a liquid crystal on silicon ("LCOS").

Item 45. The lidar system defined in any of items 1 through 44, wherein each computer-generated hologram comprises first hologram data defining the size and shape of the optical footprint and the image within the scene. A lidar system including second hologram data defining a location of an optical footprint.

Item 46. The lidar system as defined in any of items 1 to 45, wherein the first hologram data comprises a lenticular function.

Item 47. A lidar system as defined in any of items 1 to 46, wherein the second hologram data comprises a grating function.

Item 48. The lidar system defined in any of items 1 to 47, wherein the lidar system outputs a first spatially modulated light corresponding to the first computer generated hologram of the plurality of computer generated holograms and reflects from the object. And a processor arranged to determine a distance from the lidar system to an object in the scene by measuring a time difference for detecting the first spatially modulated light.

Item 49. A lidar system as defined in any of items 1 to 48, wherein the light detector comprises one of a single photodetector element or an array of photodetection elements.

Item 50. A lidar system as defined in any of items 1 to 49, wherein at least one of the spatial light modulator and the light detector is a li located within a lamp unit of a vehicle or a portable device. system.

Item 51. A lamp unit comprising a lidar system as defined in any of items 1 to 50.

Item 52. A vehicle comprising a lidar system as defined in any of items 1 through 51.

Claims (12)

A lidar system for light detection and surveying arranged to scan a scene, the system comprising:
A light source arranged to output light having a first characteristic;
A spatial light modulator ("SLM") arranged to receive light from a light source, said spatial light modulator ("SLM") comprising: a spatial light modulator arranged to output spatially modulated light according to a computer-generated hologram represented on said spatial light modulator;
A hologram controller arranged to output a plurality of computer generated holograms to the spatial light modulator, wherein each computer generated hologram is arranged to form a corresponding light footprint within the scene, the hologram controller in the scene; A hologram controller disposed to change the position of the optical footprint in the apparatus; And
A photo detector arranged to receive light having a first characteristic from the scene and to output a light response signal
Lidar system comprising a. The holographic controller of claim 1, wherein the plurality of computer generated holograms comprise a plurality of first computer generated holograms arranged to provide a first scanning in the scene, wherein the hologram controller is configured to respond to the optical scanning in response to the first scanning. A lidar system that receives a signal and determines a plurality of second computer-generated holograms based on attributes of the optical response in response to the first scanning. The system of claim 2, wherein the plurality of second computer generated holograms are arranged to provide a second scanning in the scene. 4. The system of claim 3, wherein the first scanning is scanning of a first area of the scene and the second scanning is scanning of a second area of the scene. 5. The method of claim 3 or 4, wherein the first scanning is scanning the first area of the scene in a first direction, and the second scanning is scanning the first area of the scene in a second direction. Lidar system. 6. The method of any of claims 2 to 5, wherein the plurality of first computer generated holograms are arranged to form a first optical footprint having a first area, wherein the plurality of second computer generated holograms are second areas. And a first region and a second region, wherein the first region and the second region are different regions. 7. The system of claim 6, wherein the first optical footprint has a substantially one-dimensional shape extending in a second direction, and wherein the second optical footprint has a substantially one-dimensional shape extending in a first direction. Is system. The computer-implemented hologram of claim 1, wherein the plurality of computer-generated holograms form a first computer-generated hologram arranged to form a first optical footprint at a first location in the scene and a second optical footprint at a second location in the scene. And a second computer-generated hologram, wherein the output of the second computer-generated hologram is immediately following the output of the first computer-generated hologram. 10. The system of claim 8, wherein the first location is spatially separated from the second location. 10. The system of claim 9, wherein the first location is substantially adjacent to the second location. The system of claim 8, wherein the optical footprint is continuously repositioned to scan the optical footprint within the scene. 12. The method of any one of claims 8-11, wherein the first optical footprint has a first region and the second optical footprint has a second region, wherein the first region and the second region are different. Lidar system that is an area.

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